Talking-machine



' J. A. DAVIS.

TALKING MACHINE.

APPLICATION FILED 050.3, 1919.

1,334.,690 Patented Mar. 23, 1920.

ma aia Gum," e1,

UNITED stra ns Pa rENT OFFICE.

JOHN A. DAVIS, or THE UNITED STATES NAVY, nssrenon or ONE-HALF T0 FRED s. LINCOLN, OF WASHINGTON, DISTRICT or COLUMBIA.

TAI KING-MAGHINE.

menace.

Specification of Letters Patent.

Patented Mar.- 23, 1920.

Application filed December 3, 1919. Serial No. 342,163.

dress is Navy Department, lVashington,

ll. C, have invented certain new and useful. Improvements in Talking-Machines, of which the following is a specification.

This invention relates to improvements in talking machines, and more particularly in the record-carrying elements, or turntables, comprised therein. The invention aims, generally, to overcome various defects of a more or less recognized and serious character inherent in the ordinary forms of turntables now in use, and, in brief, toimprove the tonal. qualities of reproduction and to. prolong the effective life of the mechanism.

At the present time, it is usual to construct talking machine turntables of either cast or pressed metal. But because of the inherent resonance of the metal- Which varies, of course, in the dilferentmetals em- ')loyed-and, of the formation of the depending flange which is provided at the edge of the table for coaction with the brake, the structure produced constitutes in reality .a. bell and. like one, tends to increase the already resonant quality of the metal.

Hence it necessarily follows that any me chanical'noise which may be set up from any cause In the driving mechanism of the instrument, or which may be transmitted thereto from some extraneous source, will travel through the driving mechanism to the spindle and thence to the turntable,

machines, it is particularly an incident of machines of thelatter type inwhlch the ro tating element of the motor attains amuch higher speed than the spring unit of the is formed in the upper face of the table con-- first-mentioned type and for that reason produces a more audible noise, in addition to such noises as may possibly be created by the passage of the electric current. Moreover, it has been demonstrated that in many instances vibrations other than those coment in the record itself from one cause or another and become audible during repro-' duction, thus tending to impair the reproduction of the composition, so that from both a theoretical and from a practical standpoint, perfect reproduction has not as yet been obtained if, indeed, it is notactually impossible.

My invention seeks to improve reproduction by avoiding as far as now seems possible all of the additionalor independent vibrations above referred to, this object being. effected by the provision of a specially-constructed turntable which is not only devoid of any and all resonance, but which also blocks or prevents the passage of extraneous vibrations through it to the record. Furthermore, the construction of the turntable is such that it is not apt to springor bend when pressure is imposed upon it, nor to get out of true after having been used for some time; but, on the contrary, its desired fine dimensions may be followed more carefully than hasheretofore been regarded possible, and it will preserve its shape and dimensions and will run with a degree of trueness Which enables it to be positioned extremely close to the deck of the'cabinet without the slightest danger of interference during its rotation.

It' is a further object of the invention to provide table of the above character and having the properties or qualities mentioned, which may 'be adjusted with nicety as to its weight, so that it may be made heavier or lighter, according as conditions require,

without departing in any Way from its pre- 1 scribed dimensions.

Another feature of the invention is the construction of the table in such a way that finger-spaces are provided which readily enable disk records of the two standard or stock sizes (ten and twelve inches) to be re'zztdilyv lifted off the table at the conclusion of reproduction. In the case of a 10- inch disk, the lifting space is constituted by an annular groove, channel or recess which centric with the spindle, and which is so positioned with respect" thereto that the edge of the disk overhangs the deepest part of the groov -e, the latter being wide enough to permit the fingers to be slipped under the disk. The space for the large or 12inch disks is p ovided at the peripheral edge of v and 2 the usual deck. motor board or panel the table and is formed by inclining that edge upwardly and inwardly so that the upper edge of this inclined wall or face is disposed an appreciable distance nearer the center of the table than the Outer or lower edge, the result being that the edge of the disk will project beyond the upper edgeof the inclined face of the table and, hence, can easily' be lifted from the table by inserting the fingers into the space provided by the overhang.

A still further object of the invention is toobviate danger of the needles or styli working under the table and falling into the driving mechanism. In the conventional forms of machine now in general use, this is apt to happen, with injurious results to the mechanism, both during changing of the needles and when needles are left upon the deck of the cabinet instead of being kept in boxes, cups or the like. According to my invention, I interpose directly between the edge of the turntable and the deck an annular strip of molding which forms an upstanding guard ridge, rib or shoulder, such strip preventing the needles from passing into the space beneath the table; Moreover, the outer face of the strip has exactly the same inclination as the edge face of the table, so that one forms a continuation of the other, so to speak, and there is no interruption or gap which might permit the entry of the needles and which would certainly mar the artistic appearance of the instrument, the prolonged inclined surface thus provided having the added function of a deflector which shunts the needles away from the table. 1

Other and further objects and advantages will appear in the course of the following description; but it is to be understood that no limitation to the precise structure herein disclosed is contemplated or intended, but that modifications and changes may readily be made within the scope of the invention as subsequently claimed. Parts of the invention may also be used to the exclusion of others, and .in other and different environments.

In the accompanying drawing.

, Figure 1 is a fragmental plan view of a turntable constructed in accordance with the invention. showing also a portion of the deck or motor board wh'ereon it is mounted:

Fig. 2 is a diametric section; and

Figs. 3 and 4 are fragmental sectional views of modifications of certain features of the invention.

Referring more particularly to the drawing. 1 designates the turntable as a whole.

of a talking machine of conventional form. the-turntable belng mounted in the ordinary way on a vertical spindle 3 which PIOJGLTS through an opening 4 in the deck and is connected to'be driven from the motor, the

latter being either of the spring type or electrically controlled, according as may be preferred.

The turntable 1, instead of being constructed of metal, as is usually the case, is molded from a composition which, when solidified, is completely inert to sound vibrations, so that during reproduction it will be devoid of resonance and will neither transmit extraneous vibrations imparted to it, nor itself create and transmit vibrations. Such a composition is described in my prior Patent No. 1,298,019, granted March 25, 1919, and may consist, as therein stated, of pulverized asbestos, mica, gum shellac and asphaltum. Itjai s plastic when heated and can be molded under heavy pressure, and on cooling is ri id, strong,

hard and an insulator capable. o withstanding a relatively high voltage. Other compositions of an analogous or equivalent character may be used, however, in place of that just described, as the present invention does not concern itself with the actual ingredients or elements comprised in the composition.

Under certain circumstances for instance in certain makes of machines, a table constructed of the above-described composition and having the usual dimensions, may prove too light; and to remedy that possible defect, it may be advisable to weighten the table without, however, varying its working dimensions. According to my invention, I may employ one or more thin plates. rings or disks of steel or other material having sufliciently high specific gravity, which are set into the upper face of the table so as to be partly or entirely covered by the usual strip of felt, plush or 'velour'with which the table is faced. These plates may vary in thickness from 1/32 to 5/64 of an inch, and since they can be readily stamped or otherwise constructed from sheet stock of different thicknesses, it will be understood that a plate of the exact dimensions required may be obtained and in that way enable the weight of the table to be accurately and nicely adjusted to suit particular conditions.

In the present instance, two plates. indicated at 5 and 6, are represented. These plates are arranged concentrically. and the inner one 5 occupies the center of the turntable and has the form of a circle. while the outer one 6 has the form of a ring or annulus. the inner edge of which virtuall contacts with the outer edge of the circular inner plate. The latter plate is of comparatively small diameter and is set slightly below the plane of the outer plate. as shown in Fig. 2. the diameter of the said outer plate being approximately half that of the turntable. so that an annular space of the same width as the outer plate will be left between the outer edge of that plate and the edge of the turntable.

y The peripheral edge 7 of the turntable is inclined inwardly and upwardly, as has already been stated, and for the reasons previously explained. In the construction shown in Figs. 1 and 2, the inclination takes the form of a plane bevel, but it will be understood that this is only one form of many which might be adopted; for instance, the inclined face, instead of being plane or beveled, might be stepped, as indicated at 7 in Fig. 3, or curved, as indicated at 7 in Fig. 4, and in the latter case it might be either concave or convex, or a combination of the two. I In any instance, however, the main essential is the same-that is to say, the face will be inclined inwardly and upwardly-so that the lower diameter of the table will be slightly greaterthan the upper diameter; and in practice, the projection of the inclined face upon the horizontal will have a width of about 1/2 inch, though it may be slightly greater or less than that width if deemed advisable. It is preferable to make the lower diameter of the table somewhat greater than the diameter of the large-size standard disk record (12 inches), and the upper diameter sufficiently less than that of the record to enable an appreciable portion (say between 1/4 and 1/2 inch) of the record to project beyond the .upper edge ofthe turntable and thus overhang the'inclined face 7 so that it will be a simple matter to insert the fingers in the annular space provided between the said inclined face and the edge of .the record and then lift off the record. For convenience of showing, two records have been indicated in dotted linesat 8 and 8 in Figs. v1 and 2, the larger record 8 being the standard 12-inch size, and the smaller record 8 being the standard 10-inch size.

The finger space for lifting off the 10-inch record 8' is provided by means of an annular groove 9 which is formed in the upper face of the table in the portion or space between the outer edge of the plate 6 and the upper edge of the inclined face 7, and is disposed concentrically of the table. groove may be of any suitable depth, depending, of course, upon the thickness of the table, and it'is so positioned in the tlbOVQ-IDQlltlOllQtl annular portion or space that the edge of the record will project partway across it and terminate approximately above its median line, which is its point of greatest depth, the groove being of arouate section, as represented.

The usual strip 10 of felt, plush, velour or other fabric is applied to the table top,

and overlies the two plates or disks 6 and It is here shown as circular in shape and This as fitted at its edge in an annular depression 11 of the character shown and described in my above-identified patent, to which reference may be had for a complete understanding of this feature, it being deemed sufiicient for all present purposes to state that the said edge of the fabric strip is thus disposed below the olane of the table top, whereas the body 0' the fabric lies upon the plate 6 and, hence, is slightly elevated above the table top. The depression 11 is located between the inner edge of the groove 9 and the outer edge of plate 6; and between the outer edge of the former and the upper edge of the inclined face 7 there is provided a second concentric annular groove 12. This groove 12 is comparatively narrow, and is formed with'a convex bottom, the side edges of which unite with the adjacent side walls of the groove in forming two continuous annular depressions 13 which are of the same general character as the depression 11. The aforesaid convex bottom is faced with a strip 14 of felt or other fabric, the edges of which fit in the depressions 13; the arrangement being such, therefore, that the median line of the fabric strip will be disposed slightly above the plane of the table top while its edges will occupy a position below such plane. Hence, when a 12-inch record is deposited upon the turntable, it will rest upon the body of the main fabric strip 10 and the top portion of the narrow auxiliary strip 14 and will extend across the lifting groove 9, but will not touch the edges of either groove 9 or 12.

In order to prevent the entry of the needles or styli beneath the turntable, I utilize the annular ridge, rib or shoulder previously mentioned. This element, which is indicated at 15, is preferably in the form of a strip of molding and is mounted in some suitable manner upon the deck 2 immediately beneath the edge of the turntable. It is substantially trapezoidal in section, and its flat top face is located in close proximity to the flat bottom face of the table. Consequently. the space beneath the table is blocked at its entrance, so that the possibility of the needles finding their way into such space is entirely avoided, there being only the narrow crevice between the confronting edges of the strip and the table through which they could be admitted, and that crevice, as will be observed, is located above the deck. The outer side face 16 of the guard strip is preferably inclined in such a way as to maintain the continuity of inclination of the corresponding face 7 of the table, the characteristic feature of the inclined surface of the table being carried out and preserved in the guard strip, so that each constitutes an exact continuation of the other. Thus, in the case of the plane or beveled surface 7 of the table, the face 16'of the guard strip is likewise made plane; and where the surfaces are either stepped or curved, as indi-- cated at 7 and 7 in Figs. 3 and 4, the

parent from the foregoing, and further description is accordingly omitted.

I claim as my invention 1. A talking machine turntable, comprising a non-metallic body having a metallic weighting inset.

2. A talking machine turntable, comprising a body of insulating material having a metallic weighting inset.

3. A talking machine turntable, comprising a body of non-resonant, non-metallic material having a metallic weighting inset.

4:. A talking machine turntable, comprising a non-metallic body having a weighting inset embedded in it. 7

5. A talking machine turntable, having its peripheral edge inclined inwardly and upwardly to produce an annular finger-space which is overhung by the edge of a record disk of large stock size to facilitate the removal of the disk from the turntable.

6. A talking machine turntable, having a concentric circular groove formed in its upper face in position to be overhung at its point of greatest depth by the edge of'a record disk of small stock size, whereby an annular finger-space will'be produced beneath said disk edge to facilitate the removal of the disk from the turntable.

7 A talking machine. turntable having its peripheral edge inclined inwardly and upwardly to produce anannular finger-space which is overhung by the edge of a record disk of large stock. size to facilitate the renioval of the disk from the'turntable, and also having a concentric circular groove formed in its upper face in position tobe overhung by the edge of a record disk of small stock size so as to produce an annular finger-space immediately below the edge of the last-named disk to facilitate its removal from the turntable.

8, In a. talking machine, the combination, with a cabinet and a motor deck formed with a central opening; of a turntable located above the deck and having its peripheral edge inclined inwardly and upwardly; a spindle for the turntable extending up wardly through said opening; and an annular ridge mounted upon said deck immediately below the edge of the turntable, the outer face of the ridge having an inward and upward inclination which constitutes a continuation of the inclined edge of the turntable.

9. In a talking machine, the combination, with a cabinet and a motor deck formed with a central opening; of a turntable located above the deck and having its peripheral edge inclined inwardly and upwardly; a spindle for the turntable extending upwardly through said opening; and an annular ridge mounted upon said deck immediately below the edge of the turntable, the outer. face of the ridge having an inward and upward inclination which constitutes a continuation of the inclined edge of the turntable, the bottom face of the turntable and the top face of the ridge being disposed immediately adjacent each other and in parallel relation.

10. A talking machine turntable, having its upper face provided with concentric outer and inner annular strips of fabric, the confronting edges of the strips being spaced from each other, and the central portions of said strips occupying a common horizontal plane which is elevated above the plane of the upper face of the turntable, the space between said confronting edges being formed with a circular groove which is so positioned on the turntable that it will be immediately overhung by the edge of a record disk of small stock size.

'11. A talking machine turntable, provided at its upper surface with a definite, concentric. annular zone of limited width which lies below the plane of a disk record supported on the turntable and which is so located as to be directly overhung by the edge ofthe disk, thereby producing an annular finger space immediately beneath said disk edge to facilitate the removal of the disk from the turntable.

In testimony whereof I have hereunto affixed my signature.

. JOHN A. DAVIS. 

